[RFC PATCH 2/5] nvme-vfio: add new vfio-pci driver for NVMe device

[Lei Rao <lei.rao@intel.com>]

NVMe device has specific live migration implementation.
Add an specific VFIO PCI driver for NVMe device. Its
live migration support will be added in the subsequent
patches.

Signed-off-by: Lei Rao <lei.rao@intel.com>
Signed-off-by: Yadong Li <yadong.li@intel.com>
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
Reviewed-by: Hang Yuan <hang.yuan@intel.com>
---
 drivers/vfio/pci/Kconfig       |  2 +
 drivers/vfio/pci/Makefile      |  2 +
 drivers/vfio/pci/nvme/Kconfig  |  9 ++++
 drivers/vfio/pci/nvme/Makefile |  3 ++
 drivers/vfio/pci/nvme/nvme.c   | 99 ++++++++++++++++++++++++++++++++++
 5 files changed, 115 insertions(+)
 create mode 100644 drivers/vfio/pci/nvme/Kconfig
 create mode 100644 drivers/vfio/pci/nvme/Makefile
 create mode 100644 drivers/vfio/pci/nvme/nvme.c

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index f9d0c908e738..fcd45144d3e3 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -59,4 +59,6 @@ source "drivers/vfio/pci/mlx5/Kconfig"
 
 source "drivers/vfio/pci/hisilicon/Kconfig"
 
+source "drivers/vfio/pci/nvme/Kconfig"
+
 endif
diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 24c524224da5..eddc8e889726 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -11,3 +11,5 @@ obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
 obj-$(CONFIG_MLX5_VFIO_PCI)           += mlx5/
 
 obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/
+
+obj-$(CONFIG_NVME_VFIO_PCI) += nvme/
diff --git a/drivers/vfio/pci/nvme/Kconfig b/drivers/vfio/pci/nvme/Kconfig
new file mode 100644
index 000000000000..c281fe154007
--- /dev/null
+++ b/drivers/vfio/pci/nvme/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NVME_VFIO_PCI
+	tristate "VFIO support for NVMe PCI devices"
+	depends on VFIO_PCI_CORE
+	help
+	  This provides generic VFIO PCI support for NVMe device
+	  using the VFIO framework.
+
+	  If you don't know what to do here, say N.
diff --git a/drivers/vfio/pci/nvme/Makefile b/drivers/vfio/pci/nvme/Makefile
new file mode 100644
index 000000000000..2f4a0ad3d9cf
--- /dev/null
+++ b/drivers/vfio/pci/nvme/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NVME_VFIO_PCI) += nvme-vfio-pci.o
+nvme-vfio-pci-y := nvme.o
diff --git a/drivers/vfio/pci/nvme/nvme.c b/drivers/vfio/pci/nvme/nvme.c
new file mode 100644
index 000000000000..f1386d8a9287
--- /dev/null
+++ b/drivers/vfio/pci/nvme/nvme.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022, INTEL CORPORATION. All rights reserved
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/vfio.h>
+#include <linux/anon_inodes.h>
+#include <linux/kernel.h>
+#include <linux/vfio_pci_core.h>
+
+static int nvmevf_pci_open_device(struct vfio_device *core_vdev)
+{
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+	int ret;
+
+	ret = vfio_pci_core_enable(vdev);
+	if (ret)
+		return ret;
+
+	vfio_pci_core_finish_enable(vdev);
+	return 0;
+}
+
+static const struct vfio_device_ops nvmevf_pci_ops = {
+	.name = "nvme-vfio-pci",
+	.init = vfio_pci_core_init_dev,
+	.release = vfio_pci_core_release_dev,
+	.open_device = nvmevf_pci_open_device,
+	.close_device = vfio_pci_core_close_device,
+	.ioctl = vfio_pci_core_ioctl,
+	.device_feature = vfio_pci_core_ioctl_feature,
+	.read = vfio_pci_core_read,
+	.write = vfio_pci_core_write,
+	.mmap = vfio_pci_core_mmap,
+	.request = vfio_pci_core_request,
+	.match = vfio_pci_core_match,
+};
+
+static int nvmevf_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct vfio_pci_core_device *vdev;
+	int ret;
+
+	vdev = vfio_alloc_device(vfio_pci_core_device, vdev, &pdev->dev,
+				&nvmevf_pci_ops);
+	if (IS_ERR(vdev))
+		return PTR_ERR(vdev);
+
+	dev_set_drvdata(&pdev->dev, vdev);
+	ret = vfio_pci_core_register_device(vdev);
+	if (ret)
+		goto out_put_dev;
+
+	return 0;
+
+out_put_dev:
+	vfio_put_device(&vdev->vdev);
+	return ret;
+}
+
+static void nvmevf_pci_remove(struct pci_dev *pdev)
+{
+	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
+
+	vfio_pci_core_unregister_device(vdev);
+	vfio_put_device(&vdev->vdev);
+}
+
+static const struct pci_device_id nvmevf_pci_table[] = {
+	/* Intel IPU NVMe Virtual Function */
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_INTEL, 0x1457) },
+	{}
+};
+
+MODULE_DEVICE_TABLE(pci, nvmevf_pci_table);
+
+static struct pci_driver nvmevf_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = nvmevf_pci_table,
+	.probe = nvmevf_pci_probe,
+	.remove = nvmevf_pci_remove,
+	.err_handler = &vfio_pci_core_err_handlers,
+	.driver_managed_dma = true,
+};
+
+module_pci_driver(nvmevf_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lei Rao <lei.rao@intel.com>");
+MODULE_DESCRIPTION("NVMe VFIO PCI - Generic VFIO PCI driver for NVMe");
-- 
2.34.1